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 > Anybody run Lithium battery bank with solar

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Whangler

Northern CA

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Posted: 12/01/20 01:13pm Link  |  Quote  |  Print  |  Notify Moderator

I'm considering upgrading my solar and battery bank. On my Arctic Fox 25r trailer, I currently have a 160 watt zamp panel on the roof with a 30a zamp pwm controller. Additionally there are two 100 watt panels I place on the ground with a victron 15a mppt controller. Two 225a AGM batteries are 10 months old.
The panel wattage seems to be adequate, the batteries are up to 12.6 by afternoon, however the battery voltage is about 11.9 in the mornings after a night with 2 cpap machines running. The ugly truth, is that I need more ah in my bank.

So, my question is to those running solar / lithium with all the fixins: mppt controller, battery monitor /shunt, inverter, etc.

This looks like a pretty complex system with many possible electronic components that could fail. How do you like it? Had any problems with it?

From my calculations, I use just over 200 ah per day. That's gonna cost me an arm, and possibly a leg to implement that new system. Battle Born-Zamp-Victron seems like a sure fire combo. What are you using?

ThanksQ

naturist

Lynchburg, VA

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Posted: 12/01/20 01:21pm Link  |  Quote  |  Print  |  Notify Moderator

May I suggest going to the mobile-solarpower.com web site? Will Prowse has developed a LOT of expertise in the solar power field.

I'm not running lithium batteries, but I am fairly certain that your 360 watt array is not adequate for the task. That certainly won't get you 200 AH of power reliably. This is pretty much certain given your max voltage of 12.6 volts on your existing battery pack.

I am running with a pair of 125 AH AGM batteries, and they aren't fully charged until up to 13.0 volts. But this depends on how you are measuring that voltage. Is it via a VOM when they are disconnected from any load? Or is it by use of a battery monitor of some sort? If the latter, does your system contain a shunt? Or is it just the display from that MPPT controller?





2oldman

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Posted: 12/01/20 01:44pm Link  |  Quote  |  Print  |  Notify Moderator

48v 100ah li pack, big inverter, 800ah solar, victron monitor.

Itinerant1

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Posted: 12/01/20 01:52pm Link  |  Quote  |  Print  |  Notify Moderator

Just as a reference I'm using 175-225ah daily during late fall, winter, early spring with shorter daylight hours. I don't tilt the panels and can go long periods between full charges before either solar catches up or need a hold boost with the generator.

See sig for size of system.


12v 500ah (5,120Wh usable) , 20 cells_ 4s5p (GBS LFMP battery system). 8 CTI 160 watt panels (1,280 watts) 2s4p. Panels mounted flat on the roof. Magnum PT100 controller, Magnum 3012 hybrid inverter, ME-ARC 50. Installed 4/2016 been on 24/7/365

Second Chance

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Posted: 12/01/20 02:03pm Link  |  Quote  |  Print  |  Notify Moderator

We have the Grand Design factory 300 watt solar option (300 watt panel, Jaboni charge controller, Magnum Dimensions inverter) and two Battle Born 100AH LiFePO4 batteries. We ordered it this way to run the residential refrigerator on long travel days or when the power goes out for a while at a park (as it did here at Aberdeen Proving Ground this summer when a contractor ran over the park transformer with a Bobcat). The system does a good job at what we wanted it for. It will also run the furnace and lights overnight and recharge the batteries the next day... providing there is some sun. If you want to run a BUNCH of stuff and seriously boondock, I think you would want more wattage and amp-hours. We've had zero issues with any of the equipment, though.

Rob


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Lwiddis

South of Lone Pine, California

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Posted: 12/01/20 02:03pm Link  |  Quote  |  Print  |  Notify Moderator

175 to 225 ah daily use? That's a bunch of power.


Winnebago 2101DS TT & 2020 Chevy Silverado 1500 LTZ Z71, 300 watt solar-parallel & MPPT, Trojan T-125s. TALL flag pole. Prefer USFS, COE, BLM, NPS, TVA, state & county camps. Bicyclist! 14 year Army vet-11B40 then 11A - (MOS 1542 & 1560) IOBC & IOAC grad


CA Traveler

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Posted: 12/01/20 02:12pm Link  |  Quote  |  Print  |  Notify Moderator

Quote:

The panel wattage seems to be adequate, the batteries are up to 12.6 by afternoon, however the battery voltage is about 11.9 in the mornings after a night with 2 cpap machines running.


Battery voltage should rise to 14V+ for bulk charging and then taper down to absorb on the way to 13.4V for float. Up to 12.6V is way low for a full charge.

Experience is a fantastic teacher. Recommend you buy 2 more AGMs, a battery moniter I suggested in your other thread and learn. Then you'll have a better base of knowledge for upgrades. Start with your battery specs - what are the recommended charging voltages?


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Bob


SV K

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Posted: 12/01/20 02:25pm Link  |  Quote  |  Print  |  Notify Moderator

Hello Q,

To answer your question; I am currently at Quartzsite running on 1000amps 12v Lifepo4, 1900watts solar with all Victron controllers and inverter/chargers. This is my third coach with similar systems and this set-up is the sweetest yet, but…

I’m not sure you need to jump to lithium to meet your goals.

Lots of good questions and points brought up so far. So just to be clear you have (2)-225amp 12v AGM’s, which would be group 8d’s weighing roughly 140#’s ea. or (2)-225amp 6v AGM’s, which would weigh roughly 70#’s ea.?

If you have the 12v’s then I don’t see how they could be fully charged, at a very rough 25amps/hr peak charge as it would take 10’ish plus hours of full sun to replenish the 250 amps, indicated by the 11.9v reading in the morning.

I am guessing you have the 6v’s for a total of [email protected] and you are burning roughly a 125amps by morning if the batteries were 100% at the end of the day. Again I think the amount of solar you currently have will not allow for a full charge.

I wonder if you just need to add more solar to achieve a full charge and maybe that will be enough to get thru the night with a few extra amps left over in the morning.

If you’d like to talk lithium-PM me with your #.

theoldwizard1

SE MI

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Posted: 12/01/20 02:25pm Link  |  Quote  |  Print  |  Notify Moderator

If possible, run your CPAP on 12V (most models have a 12v power supply available).

Switch to an MPPT charge controller. Make sure you buy one that supports flooded, AGM and LiOn. 12.6V does not sound "fully charged" to me !

BFL13

Victoria, BC

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Posted: 12/01/20 02:32pm Link  |  Quote  |  Print  |  Notify Moderator

You need 200AH a day and have two 225AH AGMs. I will guess that they are 6 volt so your bank is 225AH. You can use half of that for "usable", so what you need is two more of those 6s so you can use 225 a day and recharge. Solar won't do any of that on an overcast day, so you have to be able to do it with no solar--especially with cpap in the picture.

It doesn't matter if they are Li or not, you need way more AH of a battery bank. And now you need to recharge that 200AH daily. Not likely to get that all done every day, if ever what with clouds etc. so the usual drill is generator and charger for most of it in say two hours of gen time, then solar to do the rest all day after the gen is shut down.

Doing that 200 from 50% SOC in two hours would be say a 100 amp charger running from a 3000w generator, to get say 150 done and then you need your solar to do another 50 or else leave the gen on for another two hours (amps now tapering, so gen time stretches out)

If those are 225AH 12s then they must be those monster 8Ds and you then already have enough bank. You still need to recharge what you used though.

Li is not going to change any of that, just cost you a ton of money. (Unless you believe in the "usable AH " smoke and mirrors where they try to say one 100AH Li is the same as two 100AH Flooded for usable AH--there is some advantage there, but not near double )

You also need an ammeter to be sure your AGMs are fully recharged--amps must taper to 0.5a/100AH of bank with voltage at 14.4 till you get to there. I bet you don't do that and now your AGMs are undercharged and sulphated (hope I am wrong!)

Sorry to be a party-pooper! Ignore what does not apply.

* This post was edited 12/01/20 05:00pm by BFL13 *


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